EP0599865B1 - Device for measuring rotational speed - Google Patents

Device for measuring rotational speed Download PDF

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Publication number
EP0599865B1
EP0599865B1 EP92915576A EP92915576A EP0599865B1 EP 0599865 B1 EP0599865 B1 EP 0599865B1 EP 92915576 A EP92915576 A EP 92915576A EP 92915576 A EP92915576 A EP 92915576A EP 0599865 B1 EP0599865 B1 EP 0599865B1
Authority
EP
European Patent Office
Prior art keywords
laser diode
rotational speed
measuring rotational
current range
fiber
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP92915576A
Other languages
German (de)
French (fr)
Other versions
EP0599865A1 (en
Inventor
Michael Neukirch
Eberhard Möss
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Rockwell Collins Deutschland GmbH
Original Assignee
Teldix GmbH
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Filing date
Publication date
Application filed by Teldix GmbH filed Critical Teldix GmbH
Publication of EP0599865A1 publication Critical patent/EP0599865A1/en
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Anticipated expiration legal-status Critical
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
    • G01C19/00—Gyroscopes; Turn-sensitive devices using vibrating masses; Turn-sensitive devices without moving masses; Measuring angular rate using gyroscopic effects
    • G01C19/58—Turn-sensitive devices without moving masses
    • G01C19/64—Gyrometers using the Sagnac effect, i.e. rotation-induced shifts between counter-rotating electromagnetic beams
    • G01C19/72—Gyrometers using the Sagnac effect, i.e. rotation-induced shifts between counter-rotating electromagnetic beams with counter-rotating light beams in a passive ring, e.g. fibre laser gyrometers
    • G01C19/721—Details

Definitions

  • the invention relates to a device for measuring the rotational speed according to the preamble of the main claim.
  • Superluminescent diodes are characterized by a large spectral width of the emitted light with high light output. Because of the manufacturing process that deviates from the manufacture of laser diodes and the relatively small number of items produced, superluminescent diodes are very expensive, so that the light source alone accounts for 10% to 20% of the manufacturing cost of the fiber gyroscope.
  • the invention has for its object to reduce the manufacturing costs of fiber gyros, with the same quality.
  • the use of a semiconductor laser with a short coherence length is advantageous, so that light waves that are reflected at coupling or interference points are not capable of interfering with the actual useful signals.
  • a semiconductor laser as is also used in CD players, is used, the manufacturing costs of the entire fiber gyro are considerably reduced. In order to obtain the large spectral width required for gyro operation, the laser is operated below the threshold current range. The emission spectrum then resembles that of a superluminescent diode.
  • the fiber gyro shown in FIG. 1 consists of a laser diode 1, a beam splitter 2 with a downstream photodiode 3, a polarizer 12, a beam splitter 4, a coil-like optical fiber winding 5 and a modulator 6.
  • FIG. 2 shows the light spectrum of a superluminescent diode.
  • the optical power is shown on the ordinate of the coordinate system and the wavelength on the abscissa.
  • the spectral width is determined at half the optical power, so that a bandwidth of approximately 15 nm results in the example shown.
  • the ordinate and abscissa show the same sizes as the coordinate system shown in FIG. 2. This results in a bandwidth of approx. 2 nm.
  • FIG. 4 shows the light spectrum of a CD laser diode operated below the threshold current range.
  • the fiber gyroscope can also have other optical components than shown in FIG. 1.
  • 1 x 3 couplers, 3 x 3 couplers or 4 x 4 couplers can also be used instead of the 2 x 2 couplers shown.
  • the optical components can also be supplemented by additional ones, e.g. two modulators.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Optics & Photonics (AREA)
  • Electromagnetism (AREA)
  • Power Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Gyroscopes (AREA)

Abstract

Proposed is a fibre-optic gyro whose light source is a compact-disc laser diode. The spectral width necessary for the operation of a fibre-optic gyro is achieved by virtue of the fact that the CD laser diode is operated at below the threshold-current range.

Description

Die Erfindung betrifft eine Einrichtung zur Messung der Drehgeschwindigkeit nach der Gattung des Hauptanspruchs.The invention relates to a device for measuring the rotational speed according to the preamble of the main claim.

Stand der TechnikState of the art

Aus der DE-OS 38 05 904 ist es bekannt, für die Lichtquelle von Faserkreiseln Superlumineszenzdioden zu verwenden.From DE-OS 38 05 904 it is known to use superluminescent diodes for the light source of fiber gyroscopes.

Superlumineszenzdioden zeichnen sich durch eine große spektrale Breite des emittierten Lichts bei hoher Lichtleistung aus. Aufgrund des von der Herstellung von Laserdioden abweichenden Herstellungsverfahrens und der relativ geringen Herstellstückzahl sind Superlumineszenzdioden sehr teuer, so daß allein die Lichtquelle 10% bis 20% der Herstellkosten des Faserkreisels ausmacht.Superluminescent diodes are characterized by a large spectral width of the emitted light with high light output. Because of the manufacturing process that deviates from the manufacture of laser diodes and the relatively small number of items produced, superluminescent diodes are very expensive, so that the light source alone accounts for 10% to 20% of the manufacturing cost of the fiber gyroscope.

Aufgabetask

Der Erfindung liegt die Aufgabe zugrunde, die Herstellkosten von Faserkreiseln, bei gleicher Qualität, zu senken.The invention has for its object to reduce the manufacturing costs of fiber gyros, with the same quality.

Die Aufgabe wird durch die im kennzeichnenden Teil des Anpruchs 1 angegebenen Merkmale gelöst.The object is achieved by the features specified in the characterizing part of claim 1.

Für die Funktion des Faserkreisels ist die Verwendung eines Halbleiterlasers mit kurzer Kohärenzlänge (d.h. mit großer spektraler Breite) vorteilhaft, damit Lichtwellen, die an Koppel- bzw. Störstellen reflektiert werden, nicht mit den eigentlichen Nutzsignalen interferenzfähig sind.For the function of the fiber gyroscope, the use of a semiconductor laser with a short coherence length (i.e. with a large spectral width) is advantageous, so that light waves that are reflected at coupling or interference points are not capable of interfering with the actual useful signals.

Verwendet man anstelle dieser Superlumineszenzdioden einen Halbleiterlaser, wie er auch in CD-Playern eingesetzt wird, verringern sich dadurch die Herstellkosten des gesamten Faserkreisels erheblich. Um die für den Kreiselbetrieb notwendige große spektrale Breite zu erhalten, wird der Laser unterhalb des Schwellstrombereichs betrieben. Das Emissionsspektrum gleicht dann dem einer Superlumineszenzdiode.If, instead of these superluminescent diodes, a semiconductor laser, as is also used in CD players, is used, the manufacturing costs of the entire fiber gyro are considerably reduced. In order to obtain the large spectral width required for gyro operation, the laser is operated below the threshold current range. The emission spectrum then resembles that of a superluminescent diode.

Durch den Betrieb unterhalb des Schwellstrombereiches wird zudem eine längere Lebensdauer des Lasers erreicht.By operating below the threshold current range, a longer lifespan of the laser is also achieved.

FigurenbeschreibungFigure description

Die Erfindung wird nachfolgend anhand der Zeichnung näher erklärt.The invention is explained in more detail below with reference to the drawing.

Es zeigen:

Fig. 1
den beispielhaften Aufbau einer Einrichtung zur Messung der Drehgeschwindigkeit (Faserkreisel),
Fig. 2
das Lichtspektrum einer Superlumineszenzdiode,
Fig. 3
das Lichtspektrum einer CD-Laserdiode im normalen Betrieb,
Fig. 4
das Lichtspektrum einer CD-Laserdiode, die unterhalb des Schwellstrombereiches betrieben wird.
Show it:
Fig. 1
the exemplary construction of a device for measuring the rotational speed (fiber gyroscope),
Fig. 2
the light spectrum of a superluminescent diode,
Fig. 3
the light spectrum of a CD laser diode in normal operation,
Fig. 4
the light spectrum of a CD laser diode, which is operated below the threshold current range.

Der in Fig. 1 gezeigte Faserkreisel besteht aus einer Laserdiode 1, einem Strahlteiler 2 mit nachgeschalteter Fotodiode 3, einem Polarisator 12, einem Strahlteiler 4, einer spulenartig aufgebauten Lichtleitfaserwicklung 5 und einem Modulator 6.The fiber gyro shown in FIG. 1 consists of a laser diode 1, a beam splitter 2 with a downstream photodiode 3, a polarizer 12, a beam splitter 4, a coil-like optical fiber winding 5 and a modulator 6.

Auf die Funktion eines Faserkreisels soll hier nicht näher eingegangen werden; sie wird für das Verständnis der Erfindung vorausgesetzt.The function of a fiber gyroscope will not be discussed in more detail here; it is assumed for an understanding of the invention.

Fig 2 zeigt das Lichtspektrum einer Superlumineszenzdiode. Auf der Ordinate des Koordinatensystems ist die optische Leistung und auf der Abszisse die Wellenlänge dargestellt. Die spektrale Breite wird bei der halben optischen Leistung bestimmt, so daß sich bei dem gezeigten Beispiel eine Bandbreite von ca. 15 nm ergibt.2 shows the light spectrum of a superluminescent diode. The optical power is shown on the ordinate of the coordinate system and the wavelength on the abscissa. The spectral width is determined at half the optical power, so that a bandwidth of approximately 15 nm results in the example shown.

In der Fig. 3 wird das Lichtspektrum einer CD-Laserdiode bei Normalbetrieb gezeigt.3 shows the light spectrum of a CD laser diode during normal operation.

Ordinate und Abszisse zeigen die gleichen Größen wie das in Fig. 2 dargestellte Koordinatensystem.
Es ergibt sich hier eine Bandbreite von ca. 2 nm.The ordinate and abscissa show the same sizes as the coordinate system shown in FIG. 2.
This results in a bandwidth of approx. 2 nm.

Wird die CD-Laserdiode unterhalb des Schwellstrombereiches betrieben, ergibt sich eine für den Betrieb eines Faserkreisels hinreichende Bandbreite von ca. 10 nm. Fig. 4 zeigt das Lichtspektrum einer unterhalb des Schwellstrombereichs betriebenen CD-Laserdiode.If the CD laser diode is operated below the threshold current range, a bandwidth of approximately 10 nm is sufficient for the operation of a fiber gyroscope. FIG. 4 shows the light spectrum of a CD laser diode operated below the threshold current range.

Es wird darauf hingewiesen, daß der Faserkreisel auch andere optische Komponenten aufweisen kann als in Fig. 1 gezeigt. So können z.B. auch 1 x 3 Koppler, 3 x 3 Koppler oder 4 x 4 Koppler statt der gezeigten 2 x 2 Koppler eingesetzt werden. Weiter können die optischen Komponenten durch zusätzliche ergänzt werden, so z.B. zwei Modulatoren.It is pointed out that the fiber gyroscope can also have other optical components than shown in FIG. 1. For example, 1 x 3 couplers, 3 x 3 couplers or 4 x 4 couplers can also be used instead of the 2 x 2 couplers shown. The optical components can also be supplemented by additional ones, e.g. two modulators.

Claims (1)

  1. Device for measuring rotational speed which is of the Sagnac type and has a light source, characterized in that the light source (1) is a CD laser diode (1), and in that the CD laser diode (1) is operated below the threshold-current range.
EP92915576A 1991-08-22 1992-07-14 Device for measuring rotational speed Expired - Lifetime EP0599865B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE4127859 1991-08-22
DE19914127859 DE4127859A1 (en) 1991-08-22 1991-08-22 DEVICE FOR MEASURING THE SPEED
PCT/DE1992/000572 WO1993004340A1 (en) 1991-08-22 1992-07-14 Device for measuring rotational speed

Publications (2)

Publication Number Publication Date
EP0599865A1 EP0599865A1 (en) 1994-06-08
EP0599865B1 true EP0599865B1 (en) 1995-12-27

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EP92915576A Expired - Lifetime EP0599865B1 (en) 1991-08-22 1992-07-14 Device for measuring rotational speed

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EP (1) EP0599865B1 (en)
JP (1) JP3014450B2 (en)
DE (2) DE4127859A1 (en)
WO (1) WO1993004340A1 (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2607998B2 (en) * 1991-12-03 1997-05-07 日本航空電子工業株式会社 Fiber optic gyro
DE19638203C2 (en) * 1996-09-19 1998-07-02 Bosch Gmbh Robert Optical sensor for rotational movements
KR101753317B1 (en) * 2015-09-08 2017-07-04 박현수 Ankle band for footwear

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3005645A1 (en) * 1980-02-15 1981-08-20 Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt Two current modulation of semiconductor laser - with higher current in bit stream form and lower current modulated so that sum has approximately constant power
DE3006580A1 (en) * 1980-02-22 1981-08-27 Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt Ring interferometer reflection and polarisation rotation suppression - using short source coherence time and input-output polarisers
JPS6035344A (en) * 1983-08-08 1985-02-23 Hitachi Tobu Semiconductor Ltd Light emitting device and optical signal processor using light emitting device
FR2606223B1 (en) * 1986-10-29 1996-03-01 Seiko Epson Corp SEMICONDUCTOR LASER AND MANUFACTURING METHOD THEREOF
US4887900A (en) * 1987-02-20 1989-12-19 Litton Systems, Inc. Polarization maintaining fiber interferometer and method for source stabilization
US4842358A (en) * 1987-02-20 1989-06-27 Litton Systems, Inc. Apparatus and method for optical signal source stabilization
DE3805904A1 (en) * 1988-02-25 1989-08-31 Messerschmitt Boelkow Blohm FIBER GYRO
DE3831839A1 (en) * 1988-09-20 1990-03-29 Standard Elektrik Lorenz Ag OPTICAL SEND AND / OR RECEPTION BLOCK
US4958355A (en) * 1989-03-29 1990-09-18 Rca Inc. High performance angled stripe superluminescent diode
JPH02270387A (en) * 1989-04-11 1990-11-05 Matsushita Electric Ind Co Ltd Semiconductor light emitting element

Also Published As

Publication number Publication date
JPH06510366A (en) 1994-11-17
EP0599865A1 (en) 1994-06-08
WO1993004340A1 (en) 1993-03-04
DE4127859A1 (en) 1993-07-08
DE59204864D1 (en) 1996-02-08
JP3014450B2 (en) 2000-02-28

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